Azalea plant named ‘Ospo’

ABSTRACT

A new and distinct cultivar of Azalea plant named ‘Ospo’, characterized by its upright and outwardly spreading plant habit; glossy and very dark green-colored leaves; freely branching habit; red-colored double flowers; and excellent postproduction longevity.

Botanical classification/cultivar designation: Rhododendron simsii‘Ospo’.

BACKGROUND OF THE INVENTION

The present Invention relates to a new and distinct cultivar of Azalea,botanically known as Rhododendron simsii, and hereinafter referred to bythe name ‘Ospo’.

The new Azalea is a naturally-occurring whole plant mutation of theRhododendron simsii cultivar Otto, not patented. The new Azalea wasdiscovered by the Inventors in February, 1998, in a controlledenvironment in Bad Homburg, Germany. The new Azalea was discovered andselected by the Inventors as a flowering plant within a population ofplants of the parent cultivar.

Asexual reproduction of the new Azalea by terminal cuttings taken in acontrolled environment in Sassenburg, Germany since April, 1999, hasshown that the unique features of this new Azalea are stable andreproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The new Azalea has not been observed under all possible environmentalconditions. The phenotype may vary somewhat with variations inenvironment such as temperature, daylength and/or light intensitywithout, however, any variance in genotype.

The following traits have been repeatedly observed and are determined tobe the unique characteristics of ‘Ospo’. These characteristics incombination distinguish ‘Ospo’ as a new and distinct cultivar:

1. Upright and outwardly spreading plant habit.

2. Glossy and very dark green-colored leaves.

3. Freely branching habit.

4. Red-colored double flowers.

5. Excellent postproduction longevity.

Plants of the new Azalea are most similar to plants of the parent, thecultivar Otto. Plants of the new Azalea differ primarily from plants ofthe cultivar Otto in flower color.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying colored photographs illustrate the overall appearanceof the new Azalea.

These photographs show the colors as true as it is reasonably possibleto obtain in colored reproductions of this type. Colors in thephotographs may differ slightly from the color values cited in thedetailed botanical description, which accurately describe the colors ofthe new Azalea.

The photograph at the top of the sheet comprises a side perspective viewof a typical flowering plant of ‘Ospo’.

The photograph at the bottom of the sheet is a close-up view of typicalleaves and flowers of ‘Ospo’.

DETAILED BOTANICAL DESCRIPTION

The aforementioned photographs and following observations andmeasurements describe plants grown in Sassenburg, Germany in aglass-covered greenhouse under commercial production conditions. Duringthe production of the plants, day temperatures were about 16° C. andnight temperatures were about 10° C. Plants were pinched three timesduring the production of the plants. Plants used for the photographs anddescription were about 22 months from planting rooted young plants.

In the following description, color references are made to The RoyalHorticultural Society Colour Chart, 1995 Edition, except where generalterms of ordinary dictionary significance are used.

Botanical classification: Rhododendron simsii ‘Ospo’.

Parentage: Naturally-occurring whole plant mutation of Rhododendronsimsii cultivar Otto, not patented.

Propagation:

Type.—By vegetative cuttings.

Time to initiate roots.—Summer: About 35 days at temperatures of 24° C.Winter: About 42 days at temperatures of 24° C.

Time to develop roots.—Summer: About 63 days at temperatures of 18 to20° C. Winter: About 77 days at temperatures of 8° C.

Root description.—Fine; brown in color with white-colored root tips.

Rooting habit.—Freely branching; vigorous.

Plant description:

Plant form and growth habit.—Perennial, evergreen; upright and outwardlyspreading plant habit; inverted triangle; uniform and symmetrical planthabit; moderately vigorous growth habit. Densely foliated. Freelyflowering; numerous flowers per plant.

Branching habit.—Freely branching; about six lateral branches developafter pinching (removal of terminal apex).

Plant height, soil level to top of flowers.—About 17 cm.

Plant diameter, area of spread.—About 32 cm.

Lateral branch description.—Length: About 12 cm. Diameter at base: About2 mm. Texture: Sparsely pubescent. Color: Young: 145C. Mature: 164A.

Foliage description.—Arrangement: Alternate, single. Length: About 3 to6 cm. Width: About 1 to 2.2 cm. Shape: Elliptic. Apex: Mucronate. Base:Attenuate. Margin: Entire. Venation pattern: Pinnate. Texture, upper andlower surfaces: Leathery; pubescent. Color: Young foliage, uppersurface: 146A; glossy. Young foliage, lower surface: Close to 146C.Fully expanded foliage, upper surface: Darker than 147A; glossy. Fullyexpanded foliage, lower surface: Close to 147B. Petiole: Length: About7.5 mm. Diameter: About 2 mm. Color, upper and lower surfaces: Close to146D.

Flower description:

Natural flowering season.—Spring after sufficient cool period. Flowerspersistent.

Flower arrangement.—Double flowers arranged singly at terminals withusually about three to four flowers per apex; freely flowering. Flowersface upward and outward. Flowers not fragrant.

Flower diameter.—About 6 cm.

Flower depth.—About 3 cm.

Postproduction longevity.—Plants maintain good flower substance for morethan four weeks.

Flower bud (before showing color).—Rate of opening: About three to fourdays depending on temperatures. Length: About 1.5 cm. Diameter: About 8mm. Shape: Ovoid. Color: 53D.

Petals.—Arrangement: Double flower form; one outer whorl of about fivefused petals surrounding about five petaloid structures that areirregular in size. Length, petals: About 2.5 cm. Width, petals: About2.6 cm. Shape, petals and petaloids: Broadly oblong. Apex, petals andpetaloids: Broadly acute. Base, petals and petaloids: Fused. Margin, allpetals: Entire. Texture, upper and lower surfaces: Smooth, velvety.Color: When opening and fully opened, upper surface: 47A; towards base,47D to close to 155D. When opening and fully opened, lower surface: 47B.

Sepals.—Arrangement/appearance: Single whorl of five sepals fusedtowards base into a star-shaped calyx. Length: About 4 to 5 mm. Width:About 2 to 3 mm. Shape: Ovate. Apex: Acute. Margin: Entire. Texture,upper and lower surfaces: Smooth, glabrous. Color, upper and lowersurfaces: 145C.

Peduncles.—Length: About 1 cm. Diameter: About 3 mm. Angle: Mostlyupright. Strength: Flexible; strong. Texture: Pubescent. Color: 145C.

Reproductive organs.—Androecium: Stamens transformed into petaloidstructures; occasionally one or two true stamens. Anther length: About 2mm. Anther shape: Oblong. Anther color: Close to 79B. Amount of pollen:None observed. Gynoecium: Quantity of pistils: One per flower. Pistillength: About 2 cm. Style length: About 2.2 mm. Style color: 52C. Stigmashape: Rounded. Stigma color: Close to 165B. Ovary color: 145D; heavilywhiskered.

Fruit/seed.—Fruit and seed production has not been observed.

Temperature tolerance: Plants of the new Azalea have been observed totolerate temperatures from 2 to 38° C.

Disease/pest resistance: Plants have not been observed to be resistantto pathogens and pests common to Azaleas.

It is claimed:
 1. A new and distinct Azalea plant named ‘Ospo’, asillustrated and described.